Hermetically sealed electric switch



March 6, 1951 H. KEROES HERMETICALLY SEALED ELECTRIC SWITCH Filed Marcha0, 1948 S mpm l= zi w B 0 w R W 7 E M K 1 O 3 .II o o m E z B m R E H 5Z O 9 B G 2 Z 2 2 II p Q F 6 L o 3 3 3 3 5 n m 3 Patented Mar. 6, 1951Herbert I. Keroes, Irvingtom. J"

assignor: to:

The Daven Company, NewarkpNaJi,,azcorpora tion of New Jersey ApplicationMarch 30, 194f8', S.e riaENo. 17,883.

Claim; (Cl. Ma-.416)? This invention relates to electrical switches oranalogous structures and, more particularly to a hermetically sealedpotentiometer, step switch, on the like.

An object of the presentinvention is to'providea potentiometer, stepswitch, or the like, wherein electric current flow-controlling elementsare hermetically sealed'"' in an air-tight container to protect themechanism or: parts;

thereof from affect. by: fluctuation of humidity, corrosive vapors,fungus growth or: otherdeleterious conditions, while at the same timepermitting adjustment of electric current flow-controlling elements fromthe exterior of the hermetically sealed switch structure withoutaffecting the seal of the structure.

More specifically, the present invention embodies a hermetically sealedoperating mechanism for operating or adjusting the moving arm of apotentiometer, step switch, or the like.

With these and other objects in view, as may appear from theaccompanying specification, the invention consists of various featuresof construction and combination of parts, which will be first describedin connection with the accompanying drawings, showing a hermeticallysealed electric switch of a preferred form embodying the invention, andthe features forming the invention will be specifically pointed out inthe claim.

In the drawings:

Figure 1 is a side elevation of the hermetically sealed electric switchstructure.

Figure 2 is an end view of the switch structure.

Figure 3 is a longitudinal section through the switch structure taken onthe line 3-3 of Figure 2.

Figure 4 is a cross section through the switch structure taken on theline l4 of Figure 3.

Figure 5 is a side elevation of a modified form of the switch structure.

Figure 6 is a, vertical section through the modified form of the switchstructure and taken on line li-6 of Figure 5.

Referring more particularly to the drawings, I indicates a fragment of ahermetically sealed casing in which the potentiometer, step switch oranalogous structure is mounted. The potentiometer or switch structureincludes the stationary electric current flow-controlling element 2 andthe movable flow-controlling element or switch arm 3. The switch arm 3is pivotally connected as shown at 4 to an arm 5 which is, in turn,pivotally connected to the attaching plate 6 by means of which thepotentiometer or switch structure is attached? to the" interior" of" thehousing I. In Figures- 1 to 4- of'tlie drawings the movable el'e--mentor switch arm 3 has-a contact I on its free ends which engagesvarious-coils of'the element I'- for" controllingthe flow of electricalcurrent.

An" operating rod 8 is pivotally connected to the lever 3': intermediateits ends, as shown at- 9; The. operati'ngrod 8 extends through anopening H1 in a substantially cylindricalhousing H The housing M'- issoldered orotherwise zattached with a: fluid-tight-seal-to the attachingplate 6 and to the outside of the housing I. The outer" end of thecylindrical housing H is open and it is provided with screw threads l2on its outer surface extending inwardly a short distance along thelength of the housing II. A closure and adjusting cap I3 is threaded onthe housing I l and telescopes thereover upon rotary movement, throughthe medium of the screw threads I2.

The operating rod 8 has a head [4 attached to its outer end, the outersurface of which is preferably rounded and is engaged by the innersurface of the end of the adjusting closure cap 13. A-fiexible bellowsl5 has the perimeter of its outer end attached to the head M with afluid-tight seal and the perimeter of its inner end is attached by afluid-tight seal to the inner surface of the inner end of the housing IIand, thus, the operating rod 8 extends through a hermetically sealedflexible bellows to the head l4 so that by longitudinal adjustment ofthe cap l3 on the cylindrical housing H through the medium of thethreads l2 the switch lever 3 will be moved upon its pivotal point 9.The bellows l5 embodies sufficient spring tension to force the rod 8outwardly and move the lever 3 as the cap I3 is threaded outwardly orrecedes on the housing I I.

If it is desired, or in the event the bellows l5 does not embodysuiiicient spring tension to effectively move the rod 8, a helicalspring I5 may be placed within the bellows 8, with one end engaging thehead l4 and the other end engaging the inner surface of the closed endof the housing H. The spring I5 will assist the rod returning force ofthe bellows l5.

Figures 5 and 6 of the drawings show a modified form of the invention,namely, one form of a step switch, and comprises a switch panel 20 ofinsulating material having a plurality of individual contacts 2| carriedthereby and spaced therealong, and a ring contact 22. The switch lever23 comprises the carrying body 24 to which the spring contact arms 25and 26 are connected through the medium of an insulating block 21. Thespring contact arm 25 is provided for contactbutton or head 3| whichcontacts the inner sur,

face of the adjustable cap 32. The cap 32 is adjustable, by means ofsuitable screw threads along the cylindrical housing 33 whichcorresponds to the housing I in the form of the invention shown inFigures 1 to 4 of the drawings and is sealed to the casing 34 in whichthe contact switch structure is mounted. A bellows 35, which is made ofspring material, has its outer end connected with a fluid-tight seal tothe cap 32 and its inner end connected with a fluid-tight seal to theinner surface of the inner end of the cylindrical housing 33 so as toform a fluid-tight flexible and expansible container surrounding theoperating rod 30 to permit adjustment of the contact arm 23 from theexterior of the casing 34 without breaking the hermetic seal of thecasing.

It will be understood that the invention is not to be limited to thespecific construction or arrangement of parts shown, but that they maybe widely modified within the invention defined by the claim.

What is claimed is:

In'a hermetically sealed potentiometer or electric switch structurehaving an electric current regulating arm, means for pivotallysupporting said arm, a housing, an operating member connected to saidarm and extending into said housing, an elastic bellows in said housingand having one end hermetically sealed to said housing and the other endhermetically sealed to said operating member, and a closure cap threadedon said housing and engaging said operating member for moving saidoperating member to move said arm and collapse or permit expansion ofsaid bellows.

HERBERT I. KEROES.

REFERENCES CITED The following references are of record in the I file ofthis patent:

UNITED STATES PATENTS Number Name Date 381,055- Creelman Apr. 10, 18881,276,715 Breidenback Aug. 27, 1918 1,496,136 Smoot June 3, 19241,802,200 Daniel Apr. 21, 1931 FOREIGN PATENTS Number Country Date 6,890Great Britain Apr. 4, 1893

